An antimicrobial coating contains an antimicrobial agent that kills, inhibits or reduces the ability of bacteria to grow on the surface of the coating. Antimicrobial coating composition is usually in a form of a liquid formulation which is applied on surfaces and dried to form a coating. Such coating is getting widely used in various areas including clinics, industry, and even home. One of the most commonly used areas with antimicrobial coatings is in clinic or hospital since the antimicrobial coatings are able to reduce the risk of disease transmission.
It is well known in the art that titanium dioxide and silver are commonly used to form antibacterial coatings. US2010/0062032 discloses a doped titanium dioxide coating composition for antimicrobial coatings, and the preferred dopants are silver and silver oxide.
US2011/0111213 also discloses a silver (Ag)-ion containing titanium (Ti) oxide coating composition having a silver content of greater than or equal to 0.2 of Ag/l of Ti to less than or equal to 0.4 of Ag/l of Ti, wherein the coating composition is X-ray amorphous and the hydrophobicity of the coating composition can be reduced persistently by illumination. A process for producing the coating comprises the steps of preparing a TiO2—Ag solution, coating a carrier material using the TiO2—Ag solution, and curing the TiO2—Ag solution that has been applied to the carrier, using a temperature equal or less than 200° C.
EP1681325 discloses a coating material which comprises titanium dioxide as a photocatalyst, apatite comprising calcium phosphate for adsorbing contaminants, a polymethoxy polysiloxane as a hydrophilic resin coating material, and also a thiosulfato silver complex as an antibacterial material. The coating formed by the coating material can convert pollutants such as various bacteria to harmless materials.
Nevertheless, the coatings from the abovementioned prior arts involve complicated process in synthesis of the coating solution. The synthesis of these conventional coatings requires elevated temperature to cure the coating solution, which increases the cost and may deteriorate the properties of the coating. In addition, some of the prior arts fail to provide coatings with high transparency, which limits the application of coating. Furthermore, these conventional coatings are easily peeled off after a period of usage, ultimately losing their functions.
Consequently, there is a need for an antimicrobial coating composition which is effective in providing antimicrobial function, easy to be manufactured, durable, stable and can be cured or dried on surface without high temperature curing.